(In [14945]) Fixed #14859 -- ITSocialSecurityNumberField and ITVatNumberField didn't handle all EMPTY_VALUES gracefully. Also converted the Italias localflavor doctests into unittests. We have always been at war with doctests. Thanks to Idan Gazit.

(In [14969]) [1.2.X] Fixed #14859 -- ITSocialSecurityNumberField and ITVatNumberField didn't handle all EMPTY_VALUES gracefully. Also converted the Italias localflavor doctests into unittests. We have always been at war with doctests. Thanks to Idan Gazit. Backport of [14945].